How to protect galaxiids?
In the ORC people believe that the main problem for galaxiid protection is that people actually don’t know that this fish exists. People of Otago should have a chance to become acquainted with their unique fish, and, secondly, learn that galaxiids are in danger and what is threatening them. Once they know about fish, they seem happy to help. So spread the word about galaxiids!
Among the most effective practical ways to conserve galaxiids are habitat protection, removal of trout from key galaxiid habitats and prevention of trout invasion. Trout removal is the most effective way for galaxiid restoration according to DOC.
Steps needed for protection of Otago galaxiids
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How you can help galaxiids in your neighbourhood?
• When repairing or replacing culverts or any in-stream structure, work with DOC to ensure that these are compatible with protecting native fish. Southern galaxiids sometimes need barriers to prevent them from being eaten by other species of fish.
• Fence off spawning areas in spring each year to protect glaxiids when they are laying their eggs.
• Protect valuable fish breeding grounds by restoring and protecting vegetation on stream banks and wetlands. Planting alongside streams also helps create shady cool habitat that galaxiids love - and it reduces nutrient run-off.
• Check, Clean and Dry to prevent the spread of aquatic pests – koi carp and aquatic weeds such as didymo can wreak havoc on our freshwater environments.
By Lan Pham
Trout eradication from headwaters
Scientists and government officials who we interviewed agreed that trout eradication should be done where it is possible. However, there are many constraints for implementing this in reality. Scientist, Dr Gerry Closs, from the Otago University, notes that it should be done only “where reinvasion by trout can be realistically prevented.”
Even the organization responsible for trout protection agrees with the necessity of trout eradication in some streams: Otago’s Fish and Game have already been involved in agreements for fish removal in certain locations and construction of fish barriers. Another rational was that trout eradication was already a successful practice in other countries. “Excellent idea that has worked already in many places. We need much more of this to restore galaxiid populations”, said biologist Dr Jonathan Waters, from the Otago University.
There are two main ways of removing trout: electrofishing or poisoning with rotenone. DOC ranger Pete Ravenscroft notes that they know how to stop trout from getting upstream and they know how to remove them. They can prioritize species for their conservation needs, electrofish trout out and put concrete weirs on the way to stop them getting back into a creek. If the ORC finds a section of creek that can be secured from trout re-invasion, then DOC will look at removing those trout. Together, they can secure populations upstream of a barrier. So the ORC is supporting trout eradication, when the situation is “right” (when stream is not an important trout fishery and it is not important for trout spawning). As it happens, the streams where non-migratory galaxiids persist now are relatively tiny and have only small trout that don’t contribute to any major fishery.
Fisherman John Dean thinks that if fishers were told that headwaters are ideal and necessary habitats for native fish, they would not be opposed to clearing these streams of game fish, because there would not be much trout fishing lost anyway.
Rotenone vs. elecrofishing
According a DOC ranger, electrofishing is time consuming in the field; however, use of fish poison rotenone requires a lot of time investment in getting resource consents, and is emotionally harder and less accepted by public. Rotenone will kill all fish. When DOC uses rotenone, they must make resource consent applications, and the ORC must access these and put conditions around them to make sure that it is done properly. Electric fishing will be more often supported by Fish and Game, and perhaps the public as trout killed in the process could be sold to market. However, if rotenone becomes more politically and socially accepted, it can effectively be used more extensively in trout removal.
Translocation of galaxiids might help to secure populations that are seriously threatened. The strategy involves relocating them to an area where they are more protected, for example above waterfalls or where other barriers are constructed above which trout are absent. The majority of non-migratory galaxiids live on private land, outside of the DOC estate, so they need to deal with the third party owners. Further, DOC land is mostly at high altitude, where as galaxiids are found mostly in low lands. Many cannot be translocated to uplands controlled by DOC because of habitat tolerances and/or need to maintain genetic separation.
Questions about protection
Even when we know much of the information needed for the protection of galaxiids, there are still conflicting issues that need to be resolved before restoration can be effective:
1) Should trout or galaxiids be the conservation priority in rivers and lakes?
2) Should galaxiids also be conserved for human harvesting, and/or available as a food for trout?
3) What practices and policies should be developed in parks and reserves (places where indigenous biodiversity is supposed to be conserved) to deal with trout, which threaten galaxiids in their native territory? (McDowall, 2006)
Steps needed for protection in a table: